\section{Related Work}
\label{sec:related}
Sora~\cite{SoraACM11} and BigStation~\cite{BigStation13} demonstrates the
feasibility of real time communication using commodity servers to implement WiFi
PHY and MAC; MAC Processor
~\cite{MACProcessor} presents an API to control
WiFi MAC layer using the abstraction of events, actions and conditions;
SoftRAN~\cite{SoftRAN13} 
addressed the requirements for logically centralized control and management. 
However, they do not provide any mechanisms to dynamically reconfigure existing MAC/PHY data paths.  

OpenRadio~\cite{openradio} discussed how to build programmable base stations, 
but these were limited by the hardware capabilities of particular DSPs. Furthermore, 
%OpenRadio provides support for only one data path at a time and 
OpenRadio does not provide any mechanisms to satisfy timing constraints of software data
paths.  

RadioVisor~\cite{RadioVisor14}
provides the algorithm to isolate PHY radio resources. It does not provide the
software architecture for actual virtualization of software data paths. 

CloudRAN~\cite{CRAN, virtual} statically associates each base station to a base 
band unit (BBU), is not programmable and does not provide centralized control. 
%erran: the following is redundant?
%To the best of our knowledge prior work does not adequately address these problems, 
%while our proposed design addresses all problems.
%
CloudIQ~\cite{cloudiq} showed that pooling resources can reduce 
the overall cost of a network, however it relied on statically allocating resources 
(rather than dynamically reallocating resources according to requirements). 


% LocalWords:  Sora BigStation WiFi PHY API SoftRAN OpenRadio DSPs RadioVisor
% LocalWords:  virtualization CloudRAN BBU CloudIQ
